


Sacrilege

by decidueye



Category: Haikyuu!!
Genre: Angel/Demon Relationship, Archangel Akaashi, Monster sex, Oral Sex, Other, demon bokuto
Language: English
Status: Completed
Published: 2019-02-16
Updated: 2019-02-16
Packaged: 2019-10-29 20:43:19
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,983
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17815190
Author URL: https://archiveofourown.org/users/decidueye/pseuds/decidueye
Summary: Fallen for a guy, fell down from the sky...Two lovers who should not have become entangled with one another, and yet here they are.





	Sacrilege

**Author's Note:**

> when you have a huge AU you know you're never going to write, artists will draw small snapshots. me, i write the sex scene.
> 
> (thanks to robin for the beta)

It was probably the scent of Koutarou’s blood that draws Keiji to the alleyway he lay in. Humans and demons smell no different, they tell him later; they hadn’t been seeking easy prey. Koutarou is hiding, desperate for somewhere quiet to spend his final moments, away from the clamouring bays of his own kind and the prying eyes of mortals. It is an ugly thing, to die when you were never supposed to, and if Koutarou is going to do it he will do it without an audience; he wants to be remembered as something bright.

He thinks the light that appears before him is his end. He manages to laugh - how ridiculous that he is met with a human image of heaven. He wonders if it is his own attempt at self comfort, or if death will bring his final punishment from Heaven. He doesn’t expect to meet his salvation.

When angels appear to humans, they tell them: “do not be afraid”. Demons never have to do this; their form is similar to a human’s, but God’s First Children were designed to inspire terror and awe in those who beheld them and are often mistaken for monsters, or the demons that angels and humans alike so abhor. Many are horrified to know this, and so they tell them, “do not be afraid, for I bring great news from our Lord”.

Keiji has never told Koutarou not to be afraid; he is their enemy, and should have every reason to be. But when Keiji first bears down on him, seven wings spread out to block the sunlight and innumerable eyes burning fierce into Koutarou’s soul, it isn’t fear that he feels, but want. He is thrown to his knees by the force of their presence and his skull feels tight, aching so hard he fears it might explode, but he does not lower his gaze. To see an angel is a rare occurrence, and even rarer for a demon of Koutarou’s low standing, and he is overcome with the need to drink in the sight until he is undone.

Keiji regards him with a slow, puzzled frown, reaching out with clawed fingertips to touch the wetness building at the corner of Koutarou’s eyes. He inhales, stung by the touch and enraptured, and reaches up to grip Keiji’s wrist, squeezing tightly in an effort to assert some kind of resistance. Immediately, though their touch continues to burn, he feels the injuries inflicted by his own kind fusing, wounds knotting back together in an agonising reversal. The blood can’t find its way back into his body and he feels his heart thudding faster in an effort to keep him upright. There’s a roaring in his ears and his vision darkens around the edges, struggling to focus on the monster in front of him.

“You don’t fear your reckoning?” Keiji asks. Their voice shakes Koutarou’s core, and his answering grin is more of a grimace, but he meets the gaze of the eyes on their face with his usual determination. More than his suffering, he  _ wants _ them, and he has never been one to back away from a challenge.

“I don’t think it’s come just yet,” he answers. 

 

And so it begins. Koutarou bears witness to more of an angel than any demon has before, and he drinks every drop of knowledge like a man parched from the desert. 

He keeps notes, and if he tries to pretend he can say that it’s to protect himself, but if that were true he might write them down.

Angels are sensitive in so many places if they allow you to get close. Right now Keiji’s moans are discordant, and Koutarou’s eardrums tremor with the foundations of his apartment building as he explores their form with fingers and tongue. His hands roam greedily across them, dipping underneath their feathers until he feels them shiver, and then licking and biting at their weak points so that Keiji comes apart beneath him. Their eyes are closed in rapture, and Koutarou can gaze to his heart’s content, pushing them to the edge and then pulling them back, leaving them gasping, chest heaving with treacherous breaths. They won’t submit to him - Koutarou knows that he could be engulfed in flames in an instant if Keiji chose, and that his position straddling their hips is just an illusion of power - but they trust him, a thousand eyes shut to allow Koutarou to pursue his whims, and the weight of it is almost too much to bear.

“Most would call you a fool…” Koutarou mumbles, his lips skirting over theirs and pressing butterfly kisses down their long, long stretch of throat that they expose to him, all the way down to their clavicle. Their chest, like the rest of them, is scarred with eyes cut to expand their vision, and when his fingers skate over their nipple two of them open, fixing on Koutarou’s face with an unmoving, fiery gaze.

“They do not know you - or me, for that matter.”

Everything Keiji says feels like a prophecy, and the faith they imbue in their words to him brings Koutarou close to tears. He presses his eyes, damp and stinging against their stomach, and Keiji’s flesh hisses, allergic to Koutarou’s corruption. Here, dwarfing his bed with their wings fanning out beneath them, Keiji looks as if they have fallen, and Koutarou’s throat tightens as he brushes his thumb across the pox his tears have left them with. He can’t help but imagine their punishment, far worse than this if they were to be found out. Koutarou would be heralded as a hero among his kind, whilst Keiji would be abandoned, and eventually forgotten.

There is nothing worse for an angel than to be forsaken by their siblings; they have already lost their father. He shouldn’t have put them in this position, Koutarou knows, and yet…

“Koutarou.” His name, spoken with glory, racks his chest to bring him out of his thoughts. Keiji’s mouth, wide and terrifying, is twisted at the knowledge of his pain. “We are here to forget all of that.”

Seeing his own sadness reflected a thousand times over is enough - he will make them smile while he can. Koutarou shakes himself, grinning and shuffling down Keiji’s thighs, a teasing tongue running over his own sharp teeth.

“You’re right,” Koutarou tells them, and Keiji huffs, because they knew that, of course they did, but his heart is freed when they smile at him. “I’m here to be the first demon ever to suck angel dick.”

Keiji laughs, and it’s another sound that Koutarou doesn’t think he should ever have been allowed to hear. The walls tremble, and Koutarou nips forward, giving them a quick and passionate kiss before sliding back down their body. Keiji is so infinite that Koutarou has no idea how they manage to fit on the bed, but somehow only his shins are hanging off the edge by the time his mouth reaches their groin.

“You’re impossible,” Koutarou mumbles into the curve of their hips, and he isn’t exaggerating. Keiji’s cock only earns the name by virtue of its placement, shape and Keiji’s permission. It is hot to the touch and surrounded in a light Koutarou can’t penetrate - he has no idea what his tongue is circling at the base, only that it makes Keiji shudder and moan, and that he wants to be lost in the sound of them forever.

“Jesus, Keiji…” Koutarou breathes, and Keiji reaches down to slap him, playful but firm all the same. It makes Koutarou’s hips twitch, and he returns his mouth to their cock with vigour, extending his tongue to cover as much of the light as he can manage, satisfied when Keiji’s head falls into his pillow with a soft thud. They moan as he drags his tongue slowly, slowly up the length of them, and then he takes the plunge, opening his mouth to take the head into it.

It burns. He hasn’t even moved yet, but Koutarou’s mouth has never felt so hot or so full, and he feels exalted;  _ obscene _ as his lips find the shape of them behind the light, tingling as if he were trying to drink electricity. He bobs his head, vision white behind his eyelids, and he is overwhelmed by the tang of their flavour, like salt on watermelon. He sucks thirstily and only finds himself wanting more, completely absorbed in the act. Dimly, he is aware of Keiji’s fingers in his hair, long nails scratching below his earlobes, but all he can do is moan, drawing more and more out of Keiji’s cock, the taste and scent of their precome making him dizzy with want. Beneath his thighs he is dripping, and as he reaches around the base of the shaft of light to find their balls he wonders if he can come like this, just from giving.

Demons were created to take, but Koutarou is sure that he was made for this and nothing else. Something higher than God, higher than the Devil, had conspired to make him, and they had made him for Keiji, to feel their pulse in his throat and hear their gasp as they scrambled to pull away from him.

“Hey…” Koutarou mumbles, hazily chasing after their cock. Precome and saliva dribbled down his chin, and the look in Keiji’s many eyes is one of delight - or abhorrence - or both. Their chest heaves and they swallow twice before speaking, voice hoarse like Koutarou had never heard it before.

“I was going to come…” they tell him. “I won’t, not until I have you.”

“You have me,” Koutarou breathes. He’s playing coy, as if he doesn’t understand their meaning, but he is still being honest, and his teasing is dwarfed by the emotions he can’t hold back. Keiji growls and the sky rumbles with them, and in a flurry of feathers Koutarou is thrown against the mattress, bouncing from the force until arms - four, no, eight - pin him down, biting away his gasp.

Keiji kisses as if they have never kissed before, only killed. They are possessive, demanding, and righteous, and Koutarou submits with ease. His back arches, allowing Keiji’s wings to fold around him. They are soft, and even though Koutarou felt them just moments ago he is surprised, because so much of Keiji is sharp and designed to hurt people like him. Keiji's feathers are the only part of them that matches his experience of them, and he relaxes in the hold of their wings as if he has come home.

Fingers find his cunt even as more squeeze his thighs, pressing his legs apart, and Keiji hisses into his mouth when they feel the wetness there, a thumb against his swollen clit as two fingers stretch him open, testing the resistance. Keiji's fingers are long and elegant, but Koutarou already knows what it's like to have his mouth full and he has no patience for preparation. 

“Didn't you want to have me?” he breathes, gasping at the stimulation. He's embarrassingly sensitive, worked up from nothing but the intensity of Keiji's gaze and the experience of  _ blowing an angel _ , and he groans when Keiji doesn't respond other than to crook their fingers, feeling out the slick that wraps around them. “I don't need any of that, I'm not fragile and I'm ready, I've been ready for centuries -  _ Keiji-!” _

Koutarou's whining is cut off when Keiji withdraws their fingers, four hands spreading his legs even wider until the stretch is enough to burn. He dimly registers the sticky wetness of their fingers against his thigh and then screams their name when Keiji enters him. They are barely halfway and their arms are shaking with self restraint, but Koutarou can offer no words of comfort or encouragement, the air pulled from his lungs, mouth wide open and head thrown back into the support of their wings. This is nothing like the sex he has had before; nothing like anything he has ever experienced.

“Koutarou,” Keiji speaks, the concern evident even through the layers of their voice, and Koutarou's eyes and ears regain their focus with difficulty. Keiji is flushed a delightful, almost human pink and sweat drips down their temple, lips and brow curved in a deep frown. Their cock - oh  _ holy hell _ , their cock - pulses heat and light inside him, and the walls of his cunt respond in kind.

_ This should kill me _ , Koutarou thinks all at once, the realization striking him as lightning to a rod,  _ I should be dead, I am dead and ascended somehow. _ His cunt is glowing with the light of an angel's cock, a sordid parody of some Renaissance painting, and his lungs feel as if they have been ripped wide open and he has all the universe to inhale.

He laughs, weak and hysterical. Keiji's frown deepens.

“I'm fine,” Koutarou assures them. “Only...look. This is sick, right?”

Slowly, all of Keiji's eyes turn downwards, taking in the sight of Koutarou's body until they reach their cock, thumbs pressing into his thighs until Koutarou thinks he can feel a pulse. They must see the source of his amusement, because their mouth quirks up for just one moment before settling into a serious line, fixing him with their piercing, earnest stare.

“This is perfection,” they tell him, and Koutarou is embarrassed to hear himself whimper. “You are perfection, and you are mine.”

Their compliments should sound ridiculous. No  _ demon _ could ever be equated with perfection, and it was something he had always taken pride in: that he was as misshapen and malformed as the world he had been born to. When Keiji speaks to him though, and he feels the soothing caress of their fingers over his thighs, he believes them.

“I'm yours,” he gasps, and Keiji begins to move.

Each thrust is a flash of light behind Koutarou's eyes, a fiery fullness within his abdomen that threatens to grow and burst out of him, so violently he fears the beginning of another universe. Above him, Keiji's mouth is parted, flecks of spit over their lower lip, but Koutarou can't savour the sight like he wants, too overwhelmed by the sensation of them inside him. He clenches, feeling them tense, and his moans grow into screams when they pick up the pace, pressing him closer within the hold of their wings.

_ Thrust. _ A wave crashes against chalk cliffs, taller than Koutarou has ever seen before, bringing chunks of rock in its wake.

_ Thrust. _ The magma above the earth's core churns and bubbles, simmering in the heat of the passion Koutarou is lost in.

_ Thrust. _ There is so much beyond this small world that Koutarou has never seen, and Keiji has seen it all, and they are sharing it with him in this one act. They are the same; they will never be the same; he does not care.

“Keiji…!” he shudders, body rippling as he orgasms. He sees creation, and Keiji comes not long after, filling Koutarou with a white-hot mercury that makes him tingle and shiver, pushing him over the edge again. They stroke him soothingly through the whole process, hazy eyes working together to watch him with concern, and with difficulty Koutarou manages a loopy smile.

Angels are monsters. This is something that Koutarou has always known, but he has never believed and scorned it more than when he is with Keiji.

“That stuff's probably poisonous,” he says after a long, long moment, when he can finally speak again. His voice is humiliatingly hoarse, making him realise just how loud he has been, and he thanks God - or the Devil, or himself - that his apartment building is mostly abandoned. Keiji shrugs and Koutarou narrows his eyes, voice cracking as he shrieks. “You knew and you did it anyway!”

“It won't kill you,” Keiji speaks dismissively, and then looks at him again. Koutarou adores their barb, but he knows that they worry he takes their words too literally. Once upon a time, he did. “I knew - that I could never harm you. That's not what He intended.”

Koutarou scoffs. “You make it sound as if we're fated, Keiji.”

The answering silence worries him, and he scrambles backwards, still caught in Keiji's wings as he scans their form. So many eyes makes them hard to read, and Koutarou sees only what he always has - infinity. “Would that be so bad?” 

Koutarou doesn't know what to say. It wouldn't, of course it wouldn't, but fate has never touched a being like him. He is not God's chosen project nor His abandoned prodigy; he simply is. Keiji has never had that luxury, and honestly, Koutarou doesn't know which he'd prefer.

“I don’t care about His intentions,” Koutarou says instead. That, at least, he can be honest about, and Keiji would expect nothing else of him. He cups Keiji’s cheek, pulling them closer to kiss them, exploring the lightness of their mouth until his lips tingle. “I only care about yours.”

“Oh,” Keiji replies. Their surprise is a the birth of a new year - fresh spring flowers and cold sunlight that stirs the earth into action. Koutarou watches them wrinkle their nose, and then they both smile together. Keiji pulls their wings back, using their arms to grab him as they sit up on their haunches. “Well, those are simple.”

“They are?”

“My intentions are to keep you.”

There is no bed that can fit the forms of Keiji and Koutarou simultaneously, but the bent frame in Koutarou’s apartment tries its best as Koutarou laughs, pulling Keiji’s body back with him until they are lying side by side. He traces the lid of their nearest eye; it is watching him, merciful and loving.

“Is that so…?” He murmurs, picking up a feather that has shed during their sex and kissing it with a secretive smile. “Then we match.”

 

**Author's Note:**

> find me on [twitter](http://twitter.com/raindryad) or my [NSFW ](http://twitter.com/treetwunk).


End file.
